fix: get resource from scope traverses parents (istio#25134)

* fix: get resource from scope traverses parents

* copyright banner

pkg/test/framework/resource/context.go

@@ -53,8 +53,9 @@ type Context interface {
 
 	// GetResource accepts either a *T or *[]*T where T implements Resource.
 	// For a non-slice pointer, the value will be assigned to the first matching resource.
-	// For a slice pointer, the matching resources will be appended.
+	// For a slice pointer, the matching resources from this scope and its parent(s) will be appended.
 	// If ref is not a pointer, an error will be returned.
+	// If there is no match for a non-slice pointer, an error will be returned.
 	GetResource(ref interface{}) error
 
 	// The Environment in which the tests run

pkg/test/framework/scope.go

@@ -104,6 +104,16 @@ func (s *scope) get(ref interface{}) error {
 		}
 	}
 
+	if s.parent != nil {
+		// either didn't find the value or need to continue filling the slice
+		return s.parent.get(ref)
+	}
+
+	if refVal.Kind() != reflect.Slice {
+		// didn't find the non-slice value
+		return fmt.Errorf("no %v in context", targetT)
+	}
+
 	return nil
 }
 

pkg/test/framework/scope_test.go

@@ -0,0 +1,96 @@
+//  Copyright Istio Authors
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+
+package framework
+
+import (
+	"fmt"
+	"testing"
+
+	. "github.com/onsi/gomega"
+
+	"istio.io/istio/pkg/test/framework/resource"
+)
+
+func TestGet_Struct(t *testing.T) {
+	res := &resource.FakeResource{
+		IDValue: "my-fake-resource",
+	}
+
+	tests := map[string]struct {
+		setup    func() *scope
+		expError error
+	}{
+		"exists": {
+			setup: func() *scope {
+				scope := newScope("s", nil)
+				scope.add(res, &resourceID{id: res.IDValue})
+				return scope
+			},
+		},
+		"parent": {
+			setup: func() *scope {
+				p := newScope("p", nil)
+				p.add(res, &resourceID{id: res.IDValue})
+				scope := newScope("s", p)
+				return scope
+			},
+		},
+		"missing": {
+			setup:    func() *scope { return newScope("s", nil) },
+			expError: fmt.Errorf("no framework.OtherInterface in context"),
+		},
+	}
+
+	for name, tt := range tests {
+		t.Run(name, func(t *testing.T) {
+			g := NewGomegaWithT(t)
+			scope := tt.setup()
+			var got OtherInterface
+			err := scope.get(&got)
+			if tt.expError == nil {
+				g.Expect(err).To(BeNil())
+				g.Expect(got).To(Equal(res))
+			} else {
+				g.Expect(err).To(Equal(tt.expError))
+			}
+		})
+	}
+}
+
+func TestGet_Slice(t *testing.T) {
+	exp := []*resource.FakeResource{
+		{
+			IDValue:    "child-resource",
+			OtherValue: "child",
+		},
+		{
+			IDValue:    "parent-resource",
+			OtherValue: "parent",
+		},
+	}
+
+	g := NewGomegaWithT(t)
+	parent := newScope("parent", nil)
+	parent.add(exp[1], &resourceID{id: exp[1].IDValue})
+	child := newScope("child", parent)
+	child.add(exp[0], &resourceID{id: exp[0].IDValue})
+	var got []OtherInterface
+	err := child.get(&got)
+	g.Expect(err).To(BeNil())
+	g.Expect(got).To(HaveLen(len(exp)))
+	for i, res := range exp {
+		g.Expect(got[i]).To(Equal(res))
+	}
+}

pkg/test/framework/testcontext.go

@@ -189,10 +189,7 @@ func (c *testContext) TrackResource(r resource.Resource) resource.ID {
 }
 
 func (c *testContext) GetResource(ref interface{}) error {
-	if err := c.scope.get(ref); err != nil {
-		return c.suite.GetResource(ref)
-	}
-	return nil
+	return c.scope.get(ref)
 }
 
 func (c *testContext) WorkDir() string {